Pulmonary hypertension

Question 1

What is pulmonary hypertension?

Answer 1

Characterised by pulmonary blood pressure above 25mmHg at rest.
And secondary right ventricular failure.

Question 2

What is a normal range for pulmonary blood pressure?

Answer 2

(MPAP) at rest = 10-14mmHg

Question 3

What are the two main pathological causes of pulmonary hypertension

Answer 3

Increased vascular resistance

Increased blood flow

Question 4

Describe the clinical presentation of pulmonary hypertension

Answer 4

Exertional dyspnoea 
Lethargy 
Fatigue 
Loud pulmonary second sound
Right parasternal heave 
As right heart failure develops: peripheral oedema and abdominal pain (due to hepatic congestion)

Question 5

Advance disease shows signs of right heart failure

What are these signs?

Answer 5

Elevated JVP
Hepatomegaly
Pulsatile liver
Peripheral oedema
Ascites
Pleural effusion

Question 6

What diagnostic tests would you do to diagnose pulmonary hypertension?

Answer 6

CXR- shows enlarged pulmonary arteries which taper distally

ECG- shows right ventricular heart failure and P pulmonale (suggestive of r atrial enlargement and cor pulmonale)

Echocardiography shows R ventricular dilation, may reveal cause

Question 7

How would you treat pulmonary hypertension?

Answer 7

Oxygen

Warfarin due to high risk of intrapulmonary thrombosis

Diuretics- oedema

Oral calcium channel blockers- pulmonary vasodilators

Treat underlying cause

Question 8

How would you treat advanced pulmonary hypertension?

Aim is to decrease pulmonary resistance

Answer 8

Oral endothelin receptor antagonists 
Prostanoid analogues
IV epoprostenol  (prostacyclin as a drug) 
Oral sildenafil (phosphodiesterase 5 inhibitor)

Question 9

How do endothelin receptor antagonists lower BP?

Answer 9

Activation of endothelin receptors causes contraction of smooth muscle in arterioles

Blocking receptors prevents vasoconstriction

Question 10

What other conditions may pulmonary hypertension be secondary to?

Answer 10

Left heart disease – valvular, systolic/diastolic dysfunction

Lung disease and/or hypoxia e.g. COPD, obstructive sleep apnoea, lung fibrosis

Thromboembolic occlusion or proximal/distal pulmonary vasculature

Multifactoral mechanisms – myeloproliferative disorders, sarcoidosis, glycogen storage disease